Skateboarding has established itself as a sport of exceptional popularity. While skateboards have been provided with various different configurations, most common standard skateboards include a generally flat board supported upon wheels. Most typically, forward and rearward trucks are attached to an underside of the board with a pair of wheels rotatably supported by each of the trucks. The trucks typically have a form of resilient coupler which allows the board to pivot relative to a plane in which the two wheels supported by the truck are supported. Hence, the board can be angled away from horizontal somewhat while keeping all of the four wheels rolling upon the ground. Such angling of the board also turns the wheels for directional control of the skateboard.
The wheels provided with the skateboard can have different configurations, and can be formed from different materials. However, most commonly skateboard wheels are made of a solid urethane material with a generally cylindrical form. This cylindrical form is defined by an inner side surface and an outer side surface which are generally circular and a tread surface therebetween which is generally cylindrical. A central axis of the wheel typically has a hollow bore passing therethrough which allows the wheels to be mounted to an axle supported by the truck. The wheels can either rotate upon the axle, generally acting in the form of a journal bearing, or can have a roller bearing fitted within the wheel with an inner race coupled to the axle and an outer race coupled to the wheel with the two races rolling relative to each other.
Most typically the urethane from which the wheels are formed has a hardness on the durometer “a” scale of between 75 and 103. Diameters for prior art skateboard wheels generally vary between about 50 millimeters and 77 millimeters. The softer urethanes generally provide greater traction and are most suitable where maneuverability is at a premium. Urethane wheels having a greater hardness are generally more desirable where greater speed is desired and where it is desirable that the wheels have longer endurance. Typical skateboard wheels have a width of generally between about 30 millimeters and 40 millimeters.
Also, skateboard wheels of the prior art vary somewhat in the degree of roundedness or abruptness that the tread surface transitions into the outer side surface and the inner side surface of the wheel. In particular, the tread surface is bordered by an outer edge adjacent the outer side surface and an inner edge adjacent the inner side surface. The outer and inner edges can be abrupt (typically 90°) or can be curved either with a small radius of curvature or relatively large radius of curvature. The abruptness of these edges influences the overall width of the tread surface which is contacting the ground. Also, this degree of roundedness influences an appearance of these prior art wheels somewhat.
The tread of prior art skateboard wheels is usually smooth. In some instances, such as with skateboard wheels provided by Birdhouse Projects, Inc. of Huntington Beach, Calif., and marketed under the “BIRDHOUSE” trademark, grooved urethane surface detail is provided to increase traction and decrease flatspotting. Such grooves are typically provided extending circumferentially with ten to twenty grooves on the tread surface and each groove being a fraction of a millimeter in depth. These grooves are so small that they quickly fill with dirt, tar and other road debris, such that the effect of such grooving on the tread of the wheel is limited.
Skateboard wheels, while varying slightly, have thus become rather standardized with the only variables being slight variations in diameter, slight variations in urethane hardness and some variations in the abruptness of the inside and outside edges of the tread surface. Accordingly, a need exists for skateboard wheels which depart more radically from standard prior art skateboard wheel configurations, to provide a superior ride, the potential for greater speed, greater mobility and responsiveness in turning, with less friction provided by the wheels so that overall ride smoothness is enhanced. Also, a need exists for skateboard wheels which have a more radically different appearance to allow skateboarders to have further avenues to express their distinctiveness through the way that their skateboards are outfitted.